Patent US1824525A successfully refreshed from Google Patents.
Patent US4705540A successfully refreshed from Google Patents.
US4705540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyimide gas separation membranes
Assignee: EIDP Inc
•
Filing: 1986-04-17
•
Granted: 1987-11-10
•
Expires: 2006-04-17
Abstract
Abstract A highly permeable aromatic polyimide gas separation membrane and the process of using it are disclosed. The aromatic polyimide has the formula ##STR1## wherein --Ar-- is ##STR2## or mixtures thereof, --X, --X 1 , --X 2 and --X 3 independently are alkyl groups having 1 to 6 carbon atoms or aromatic groups having 6 to 13 carbon atoms, and --Z is --H, --X, --X 1 , --X 2 , or --X 3 ; and R is ##STR3## or mixtures thereof.
Inventors
- 👤 Richard A. Hayes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:34
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/58; B01D71/62; B01D71/64; C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1039; C08G73/1067
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
72 words
A gas separation membrane formed of an aromatic polyimide of the formula ##STR7## where --Ar-- is ##STR8## or mixture thereof, and R is ##STR9## or mixtures thereof and --X, --X 1 , --X 2 , and --X 3 are independently alkyl groups having 1 to 6 carbon atoms or aromatic groups having 6 to 13 carbon atoms, and --Z is --H, --X, --X 1 , --X 2 , or --X 3 .
Claim 2
Dependent Claim
72 words
A gas separation membrane formed of an aromatic polyimide of the formula ##STR7## where --Ar-- is ##STR8## or mixture thereof, and R is ##STR9## or mixtures thereof and --X, --X 1 , --X 2 , and --X 3 are independently alkyl groups having 1 to 6 carbon atoms or aromatic groups having 6 to 13 carbon atoms, and --Z is --H, --X, --X 1 , --X 2 , or --X 3 .
Claim 3
Dependent Claim
25 words
The membrane of claim 1 wherein --X, --X 1 , --X 2 , or --X 3 are --CH 3 or --C 2 H 5 .
Claim 4
Dependent Claim
9 words
The membrane of claim 2 wherein R is ##STR10##
Claim 5
Dependent Claim
118 words
A process of separating two or more gases comprising of steps of bringing a mixture of two or more gases into contact with one side of a permselective membrane which is formed from an aromatic polyimide of the formula ##STR11## where --Ar-- is ##STR12## or or mixtures thereof, and R' is ##STR13## or mixtures thereof and --X, --X 1 , --X 2 , and --X 3 are independently alkyl groups of 1 to 6 carbon atoms, or aromatic group having 6 to 13 carbon atoms and --Z is --H, --X, --X 1 , --X 2 , or --X 3 whereby one of said gases permeates said membrane at a different productivity rate than at least one other gas.
Claim 6
Dependent Claim
118 words
A process of separating two or more gases comprising of steps of bringing a mixture of two or more gases into contact with one side of a permselective membrane which is formed from an aromatic polyimide of the formula ##STR11## where --Ar-- is ##STR12## or or mixtures thereof, and R' is ##STR13## or mixtures thereof and --X, --X 1 , --X 2 , and --X 3 are independently alkyl groups of 1 to 6 carbon atoms, or aromatic group having 6 to 13 carbon atoms and --Z is --H, --X, --X 1 , --X 2 , or --X 3 whereby one of said gases permeates said membrane at a different productivity rate than at least one other gas.
Claim 7
Dependent Claim
24 words
The process of claim 4 wherein --X, --X 1 , --X 2 , --X 3 are --CH 3 or --C 2 H 5 .
Claim 8
Dependent Claim
9 words
The process of claim 5 wherein R is ##STR14##
References Cited (Backward Citations)
US30351A
Cited
US3410826A
Cited
US3714131A
Cited
US3745149A
Cited
US3835207A
Cited
US3899309A
Cited
USRE30351E
Cited
US3822202A
Cited
US4113628A
Cited
US4378324A
Cited
US4378400A
Cited
US4474662A
Cited
US4512893A
Cited
GB2098994A
Cited
GB2101137A
Cited
GB2102333A
Cited
US4485056A
Cited
US4440643A
Cited
US4486376A
Cited
JPS585344A
Cited
JPS588512A
Cited
US4528004A
Cited
US4474858A
Cited
JPS57177303A
Cited
US4560742A
Cited
EP0113574A2
Cited
US4603193A
Cited
EP0132221A1
Cited
JPS6082103A
Cited
EP0141781A2
Cited
JPS60257805A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-09 | 1991-05-11 | 1991-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-09 | 1995-05-11 | 1995-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-09 | 1999-05-11 | 1999-11-10 | $7700.00 | Window Closed / Lapsed |